diff -r 0ad8b4be45cc -r 49b6723410e6 src/mem/Bus.py
--- a/src/mem/Bus.py	Tue Oct 23 10:27:59 2012 +0100
+++ b/src/mem/Bus.py	Tue Oct 23 10:30:53 2012 +0100
@@ -47,8 +47,6 @@
     abstract = True
     slave = VectorSlavePort("vector port for connecting masters")
     master = VectorMasterPort("vector port for connecting slaves")
-    # Override the default clock
-    clock = '1GHz'
     header_cycles = Param.Cycles(1, "cycles of overhead per transaction")
     width = Param.Unsigned(8, "bus width (bytes)")
     block_size = Param.Unsigned(64, "The default block size if not set by " \
diff -r 0ad8b4be45cc -r 49b6723410e6 src/sim/System.py
--- a/src/sim/System.py	Tue Oct 23 10:27:59 2012 +0100
+++ b/src/sim/System.py	Tue Oct 23 10:30:53 2012 +0100
@@ -42,11 +42,10 @@
     system_port = MasterPort("System port")
 
     # Override the clock from the ClockedObject which looks at the
-    # parent clock by default
-    clock = '1t'
-    # @todo Either make this value 0 and treat it as an error if it is
-    # not overridden, or choose a more sensible value in the range of
-    # 1GHz
+    # parent clock by default. The 1 GHz default system clock serves
+    # as a start for the modules that rely on the parent to provide
+    # the clock.
+    clock = '1GHz'
 
     @classmethod
     def export_method_cxx_predecls(cls, code):